mw13:
I disagree. Just as every person can make themselves into a good, even great person, every person can make themselves into bad person, or even a monster. We all have the ability to become a Godly saint, and we all have it within ourselves to become a monster. It’s just a question of who we choose to become.
But why would anyone choose to become a destructive monster? Besides, wicked people are full of regrets (chazal). Not being content and always regretting, yet repeating the same exact deal in the same again and again, is certainly the makeup of an unhappy etc person.